I grew up working in the DIY trade. I worked in a "proper" hardware shop, you might remember the sort, smelled a bit funny "open all hours" etc.
I will always remember I sold one single plasterboard fixing to (quite an attractive) lady and said as I rang up something like 6p on the till "it comes with a free screw", much to the absolute delight of everyone ...and the shop owner taking me aside afterwards as if going bright red at the time wasn't bad enough.
....Like I said, I was quite "niave" at the time, but I have always remembered it. Suffice to say, I'm more worldly since -but it still seems difficult to give them away?
LoL,
Rich